How severe is CVE-2021-20161?

CVE-2021-20161 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-20161 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20161?

CVE-2021-20161 affects Trendnet Tew-827dru Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20161?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-20161 published?

CVE-2021-20161 was published on 2021-12-30 and last updated on 2026-06-17.

CVE-2021-20161

CVE-2021-20161 is a medium-severity vulnerability in Trendnet Tew-827dru Firmware with a CVSS 3.x base score of 6.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: Medium (CVSS 3.x base score 6.8)
CVSS v2: 7.2
EPSS exploit prediction: 0% (16th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Trendnet Tew-827dru Firmware
Published: 2021-12-30
Last modified: 2026-06-17

Description

Trendnet AC2600 TEW-827DRU version 2.08B01 does not have sufficient protections for the UART functionality. A malicious actor with physical access to the device is able to connect to the UART port via a serial connection. No username or password is required and the user is given a root shell with full control of the device.

Frequently asked questions

What is CVE-2021-20161?: Trendnet AC2600 TEW-827DRU version 2.08B01 does not have sufficient protections for the UART functionality. A malicious actor with physical access to the device is able to connect to the UART port via a serial connection. No username or password is required and the user is given a root shell with full control of the device.
How severe is CVE-2021-20161?: CVE-2021-20161 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-20161 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (16th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20161?: CVE-2021-20161 affects Trendnet Tew-827dru Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20161?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20161 published?: CVE-2021-20161 was published on 2021-12-30 and last updated on 2026-06-17.

References

https://www.tenable.com/security/research/tra-2021-54

Affected products (1)

cpe:2.3:o:trendnet:tew-827dru_firmware:2.08b01:*:*:*:*:*:*:*

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Other CWE-287 (Improper Authentication) vulnerabilities

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CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
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